Self-adhesive washer for a bathtub or shower

ABSTRACT

A self-adhesive washer including a pressure sensitive adhesive on both sides of a center layer. The washer is preferably used to attach a drain shoe to a bathtub in combined bathtub and shower units to eliminate the need for more than one installer. The washer may be adapted to fit the shape of the drain shoe. Washers having both adhesive layers and a center layer, preferably cellular plastic, may serve both to adhere the drain shoe to the bathtub, and after completion of the drain assembly installation, to seal the drain shoe to the bathtub.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to washers and more particularly to self-adhesive washers for use in plumbing.

2. Related Art

When a bathtub or shower is shipped from a factory, it is shipped without the waste and overflow plumbing assemblies directly attached. Therefore, it is the plumbers' responsibility to assemble the waste and overflow assembly once the bathtub or shower is in place. Standard waste assemblies usually include a waste arm, a drain shoe attached to the waste arm, and possibly a rubber gasket. A standard bathtub or shower drain comprises the drain shoe and the strainer. Standard overflow assemblies usually include an overflow pipe attached to the waste arm, one or more conventional rubber gaskets, and an overflow cover plate. Standard bathtubs require less effort to install the waste and overflow assemblies because the plumber is able to reach the upper surface and the bottom surface of the bathtub at the same time by reaching over the end of the bathtub where the drain is installed and screwing in the strainer with one hand while holding the drain shoe against the underside of the bathtub with the other hand.

However, the more modern combined bathtub and shower units are manufactured to be integral or one-piece units; therefore, they require a second plumber to assemble the drain, due to the shower wall blocking the way for the plumber to reach over the end of the bathtub where the drain is installed. Further, it is too difficult for the plumber to reach around the side of the shower portion to reach the inside of the bathtub. Therefore, one person must be at the end of the bathtub and shower unit “behind” the shower wall holding the waste and overflow assemblies in place between the floor joists while another person is in the bathtub to screw in the strainer. As a result, the process of assembling the drain becomes less efficient due to the need for an additional person. Additionally, it is difficult for the plumber holding the waste and overflow assemblies to align the drain shoe with the drain hole in the bottom of the bathtub because they cannot see the drain hole due to the shower wall blocking their view.

Rubber gaskets have been used between two plumbing flanges. The rubber gaskets are loosely placed on flanges and tend to move around as the items to be joined are pulled together. Further, these gaskets are not intended to hold a flange in place, but are intended only to improve a fluid seal. Likewise, a rubber gasket is sometimes supplied with a standard bathtub waste and overflow drain assembly for sealing the drain shoe to the bathtub; however, as in the case of a gasket sealing two flanges, the gasket tends to move around on, or fall off of, the drain shoe. When successfully installed, the gasket is compressed between the drain shoe and the bathtub and serves as a liquid seal, but does not support or hold the drain shoe in place during any part of the process. Rarely, silicone may be applied to the drain shoe instead of a rubber gasket, but the silicone is not adhesive enough when wet to hold the drain shoe against the bathtub on its own and it takes too long to dry.

Provencher (U.S. Pat. No. 6,736,406) discloses a gasket having an adhesive layer on a first side and a release layer covering the adhesive layer. The installer removes the release layer and secures the gasket to the bottom surface of the sink strainer. The installer inserts the strainer with the gasket in an opening in a tub or shower floor from the inside of the bathtub or shower and then threads the strainer into the threaded portion of the drain shoe. Since the strainer needs to rotate relative to the surface of the tub or shower floor, no adhesive is applied to the lower surface of the gasket. The adhesive on the gasket is intended to hold the gasket secure relative to the strainer not to hold the strainer secure against the bathtub or shower. Further, Provencher still requires an additional person to hold the waste and overflow assemblies in place while the strainer is being threaded into the drain shoe because there is nothing to hold the drain shoe against the bathtub.

Therefore, there is still a need for a self-adhesive washer to join plumbing components together, especially the drain shoe and the bathtub, as well as a way to align the drain shoe with the drain hole without the need for an additional person.

Other issued patents relating to self-adhesive plumbing members for making a joints fluid-tight are as follows: Sylvester (U.S. Pat. No. 6,190,751) and Teranishi et al. (U.S. Pat. No. 6,328,313).

SUMMARY OF THE INVENTION

The present invention relates to a self-adhesive washer and more specifically, a self-adhesive washer for securing a plumbing flange relative to a bathtub or shower. The invention further relates to a self-adhesive washer for joining a drain shoe to the bottom surface of a bathtub, shower, or a combined bathtub and shower unit. The washer is adhesively connected to a surface of the drain shoe and the drain shoe is in turn adhesively connected to a bottom surface of the bathtub. The self-adhesive washer may be as simple as a sheet having two sides with adhesive properties. More preferably, the washer comprises a center layer of plastic, foam, or other material having some compressibility, an adhesive layer on a first side of the center layer, a first release liner covering the first adhesive layer, an adhesive layer on a second side of the center layer, and a second release liner covering the second adhesive layer. The washer is preferably adapted to fit the shape of the drain shoe.

Optionally, the self-adhesive washer may be used in combination with a centering tool. The preferred centering tool comprises a smooth portion and a threaded portion. The threaded portion is adapted to threadably engage threads on the inside of the drain shoe. The centering tool allows easy alignment of the drain shoe and washer with the drain hole.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of one embodiment of a waste and overflow assembly with one embodiment of the invented self-adhesive washer, in combination with a bathtub and shower unit.

FIG. 2 is an exploded, partial of the embodiment of FIG. 1.

FIG. 3 is a perspective view one embodiment of the preferred self-adhesive washer shown in FIGS. 1 and 2, wherein the release liners are partially removed.

FIG. 4 is a side view of the preferred self-adhesive washer without release liners.

FIG. 5 is a perspective view of one embodiment of the invented centering tool.

FIG. 6 is a side view of the centering tool shown in FIG. 5.

FIG. 7 is a perspective view of the centering tool shown in FIGS. 5 and 6 in combination with the preferred washer and drain shoe.

FIG. 8 is a partial side cross-sectional view of the embodiment of FIG. 7 installed in a bathtub.

FIG. 9 is an exploded perspective view of the embodiment of FIG. 8.

FIG. 10 is a perspective view of the embodiment of FIG. 8.

FIG. 11 is a perspective view of the embodiment of FIGS. 8 and 10 with the centering tool being removed.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the Figures, there is shown one, but not the only embodiment of the self-adhesive washer 108. FIG. 1 illustrates a combined bathtub 101 and shower 201 unit with waste and overflow assemblies 100. FIG. 2 illustrates an exploded detail view of the waste and overflow assemblies 100 in combination with the preferred self-adhesive washer 108. The bathtub 101 comprises a bottom surface 101′ and a top surface 101″. The shower 201 comprises a sidewall 201′. As shown in FIGS. 1 and 2, the waste and overflow assemblies 100 comprises a drain stopper 102, a strainer 104, an aperture or drain hole 106 for receiving the strainer 104, a washer 108, a drain shoe 110 with a top surface 111, a waste arm 112, an overflow pipe 114, a second aperture 115 for receiving the overflow pipe, and a overflow cover plate 116. The inner surface of the drain shoe 110 is threaded to match the threads of the strainer 104. The external surface of the top of the overflow pipe 114 is threaded to match the internal threads of the overflow cover plate 116.

As shown in FIGS. 3 and 4, the preferred washer 108 is a self-adhesive foam washer comprising a layer of flexible foam 120; an adhesive layer 122 on a first side of the flexible foam 120; a release liner 124 covering the adhesive 122 to protect the adhesive layer and prevent two washers from sticking together; a second adhesive layer 126 on a second side of the flexible foam 120; and, a second release liner 128 applied to the second layer of adhesive 126. Preferably, the flexible foam 120 is compressible cellular plastic. The washer 108 is shown as circular (see FIG. 3), but it may other shapes or sections of self-adhesive tape that can adhere to the top surface of a plumbing flange, especially the drain shoe 110 and securely hold the drain shoe 110 against the bottom surface 101′ of the bathtub 101. The release liners 124, 128 may be material commonly known as “release liner” (comprising release paper having a release coating, preferably silicone, which provides the release surface), or may be other material that allows the adhesive layers to be covered during storage and transport, but easily exposed for use. The pressure sensitive adhesive is selected so that it can preferably withstand heat and effectively bond the top surface 111 of the drain shoe 110 to the bottom surface 101′ of the bathtub or shower long enough for a single plumber to install the strainer 104 in the drain shoe 110. The preferred washer 108 may be made of the same material used to make Scotch® Double-Sided Mounting Tape.

The two release liners 124, 128, two adhesive layers 122, 126 and the foam layer 120 may be made as a single sheet, and then cut in the preferred shape. The length and the thickness of the sheet may be suitable for die-cutting a plurality of self-adhesive washers 108 therefrom. The preferred washer 108 has a circular inner and outer diameter. The thickness of the washer 108 and the inner and outer diameter may be modified to fit a specific device.

Other release liners, adhesive, foam or other compressible or flexible materials may be used, so long as the washer is able to adhere to the plumbing surfaces and hold the plumbing flange for a period of at least 1 minute, and more preferably, at least three minutes. While adhesive is desired that will hold the weight of the drain shoe for several minutes, the adhesive need not be a “permanent” or “semipermanent” adhesive that holds the drain shoe for hours or days. Additionally, the washer may be manufactured without a foam or other compressible layer, for example, a substantially non-compressible, thin sheet with adhesive on both sides. Additionally, the self-adhesive washer may be manufactured without release liners that are cut to the size of the washer, and instead the adhesive washer may be “stuck” to a larger piece of release liner and the washer may be peeled off when ready for use. As discussed above, the release liner, either cut to the size of the washer or as a larger sheet, may be made of the material commonly known in the tape and adhesives art as “release liner” or may be other material that allows for easy removal of the washer.

The preferred method of installing the washer 108 is to temporarily ‘hang’ the top of the overflow pipe 114 on the aperture 115. Then, or alternatively before hanging the overflow pipe on the aperture, the installer removes a first release liner 124 from the washer 108 and places the exposed adhesive surface 126 on the top surface 111 of the drain shoe 110. The second release liner 128 is removed from the washer 108, exposing the second adhesive layer 126. The drain shoe 110 with the exposed adhesive layer 126 is then adhered to the bottom surface 101′ of the bathtub 101 around the drain hole 106. One advantage of the self-adhesive washer 108 is that it will not move around relative to the drain shoe 110 as the installer is trying to attach the drain shoe 110 to the bathtub 101. Once the drain shoe 110 is adhered to the bathtub 101, the single installer can crawl into the bathtub 101 to mate the strainer 104 with the threads on the inside of the drain shoe 110.

The act of screwing the strainer 104 into the drain shoe 110 puts downward force on the drain shoe 110 and so, the adhesive must be strong enough to hold the drain shoe 110 against the bathtub surface 101′ in spite of this force. Because the washer 108 holds the drain shoe 110 against the bottom surface 101′ of the bathtub, the task of screwing in the strainer is easier, as the drain shoe 110 stays properly aligned with the drain hole 106. Conventional gaskets or silicone on top of the drain shoe surface 111 would play no role in holding the drain shoe 110 against the bathtub surface 101′ or in making the strainer 104 installation process easier. The washer 108 therefore, suspends the drain shoe 110 from the bottom surface of the bathtub 101′, by supporting part or all of the weight of both the waste and overflow assemblies 100. If the waste and overflow assemblies 100 have been temporarily hung at the upper end of the overflow pipe 114 from the aperture 115, the washer 108 need support only part of the weight of the assembly 100 in order to hold the drain shoe 110 against the bathtub and prevent if from pivoting away from the drain hole 106 and falling into the floor space below the bathtub.

After the drain is assembled, the drain stopper 102 is then placed over the stainer 104. Further, the installer can then finish installing the overflow pipe 114 in the second aperture 115 by threading the overflow cover plate 116 on the end of the overflow pipe 114. The shower 201 sidewall 201′ prevents the installer from reaching over the end of the bathtub 101 where the drain is and screwing in the stainer 104. Additionally, the installer cannot reach around the side of the of the shower 201 sidewall 201′ to reach both the bottom surface 101′ and the inside or top surface 101″ of the bathtub 101 at the same time, because the shower 201 sidewall 201′ is blocking the way. An advantage of the self-adhesive washer 108 is that it allows the installer to secure the waste and overflow assemblies 100 to the bottom surface 101′ of the bathtub 101, without requiring an additional person to hold the waste and overflow assemblies 100 while the installer screws in the strainer 104 and the overflow pipe 114. The self-adhesive washer 108 holds the drain shoe 110 against the bathtub 101 long enough for the same installer to crawl in the bathtub and screw in the stainer 104 and attach the overflow pipe 114.

An Especially Preferred Embodiment

In modern combined bathtub and shower units, the unit sits about 2″ above the flooring. Typically, a hole is cut in the flooring between the floor joists underneath the drain hole 106 for the drain shoe 110 to gain access to the drain hole 106 without abutting against the flooring. Additionally, an opening S is provided between the wall studs at the end of the bathtub where the drain is installed in order to maneuver the waste and overflow assemblies 100 for attachment to the bathtub 100.

In bathtub units without a shower, the plumber is able to view the drain hole 106, by looking over the end of the bathtub 101 where the drain is to be installed, in order to see the drain shoe 110 through the drain hole 106, allowing the plumber to better align the drain shoe 110 with the drain hole 106. However, in the combined bathtub 101 and shower 201 units, the shower side wall 201′ prevents the plumber from viewing the drain hole 106 and the drain shoe 110 through the drain hole. When using the invented washer 108, the shower side wall 201′ makes it difficult for the plumber to accurately position the washer 108 and drain shoe 110 around the drain hole 106, which can cause the plumber to accidentally stick the washer 108 and drain shoe 110 in the wrong place on the bottom surface 101′ of the bathtub 101.

As shown in FIGS. 5-8, a centering tool 300 is used to accurately center the drain shoe 110 and washer 108 around the drain hole 106 on the bottom surface 101′ of the bathtub 101. The centering tool 300 is generally cylindrical and comprises a threaded portion 305 and a smooth portion 310 (see FIG. 7). Preferably, the threaded portion 305 is adapted to threadably engage the threads on the inside of the drain shoe 310, and the smooth portion 310 is sized to fit through the drain hole 106. The centering tool 300 is shown as hollow, however, it may also be solid or semi-solid depending on which is easier to manufacture, as the interior of the preferred tool 300 serves no role in the process.

As shown in FIGS. 9-11, the especially preferred method of installing the waste and overflow assemblies 100, is to remove the first release liner 124 from the washer 108 and place the exposed adhesive surface 126 on the top surface 111 of the drain shoe 110. The plumber then threads the centering tool 300 into the drain shoe 110. The second release liner 128 is then removed from the washer 108, exposing the second adhesive layer 126. The drain shoe 110 with the exposed adhesive layer 126 with the centering tool 300 attached to the drain shoe 110 are then lined up with the drain hole 106 by moving the waste portion of the assemblies 100 around until the centering tool 300 “snaps” or slides into the drain hole 106, in turn adhering the washer 108 and drain shoe 110 to the bottom surface 101′ of the bathtub 101 around the drain hole 106 (see FIG. 10). During this process, the plumber will move the drain assembly and centering tool combination underneath the bathtub, pushing the centering tool along the bottom surface of the bathtub “tying to find” the drain hole, without being able to see the drain shoe, the centering tool, or the drain hole. When the plumber is successful in moving the centering tool and drain shoe to the drain hole, the centering tool will quickly “snap” up into the drain hole and allow the washer to contact and stick to the bottom of the bathtub. Therefore, the term “snap” is used herein, but the centering tool preferably does not frictionally bind on, or fit tightly in, the drain hole, and the centering tool may also be said “to be inserted into,” “to slide into,” “to be received in, “to engage,” or “lifted into” the drain hole, for example. The centering tool preferably has an upper portion with an outer diameter that is close to, but smaller than the drain hole diameter, for example, a diameter about ⅛-¼ inch smaller than the drain hole.

The top of the overflow pipe 114 is then “hung” from the aperture 115. Once the drain shoe 110 is adhered to the bathtub 101, the installer can crawl into the bathtub 101 and unthread the centering tool 300 with the drain shoe 110 (see FIG. 11), and then mate the strainer 104 with the threads on the inside of the drain shoe 110. Before the plumber installs the strainer, he may optionally apply silicone or plumbers putty to the bottom side of the strainer lip to create a water tight seal between the strainer 104 and the top surface 101″ of the bathtub 101. After the drain is installed the rest of the overflow assembly may be installed.

Although this invention has been described above with reference to particular means, materials and embodiments, it is to be understood that the invention is not limited to these disclosed particulars, but extends instead to all equivalents within the scope of the following claims. 

1. A drain assembly combination comprising: a drain shoe adapted for placement underneath a bathtub drain hole; and a self-adhesive washer comprising: a flexible layer having a first side and a second side; a first adhesive layer on said first side of the flexible layer; a second adhesive layer on said second side of the flexible layer; wherein said first adhesive layer is stuck to a top surface of a drain shoe; and wherein said second adhesive layer is adapted to be stuck to a bottom surface of a bathtub to secure the drain shoe up against said bottom surface.
 2. A drain assembly combination as in claim 1, wherein said self-adhesive washer comprises a first release liner on said first adhesive layer, and wherein said first release liner is removably secured to said first adhesive layer and adapted to be removed prior to attachment of the washer to the drain shoe.
 3. A drain assembly combination as in claim 1, wherein said self-adhesive washer comprises a second release liner on said second adhesive layer, and wherein said second release liner is removably secured to said second adhesive layer and adapted to be removed prior to attachment of the washer and drain shoe to the bottom surface of the bathtub.
 4. A drain assembly combination as in claim 1, wherein said self-adhesive washer is a circular shape.
 5. A drain assembly combination as in claim 4, wherein said self-adhesive washer has a circular inner diameter and a circular outer diameter.
 6. A combination of a bathtub and a drain assembly, wherein the bathtub has a bottom wall with a bottom surface, a top surface, and a drain hole through the bottom wall; and wherein the drain assembly comprises: a drain shoe underneath the bathtub drain hole and having a top surface; and a self-adhesive washer comprising: a flexible layer having a first side and a second side; a first adhesive layer on said first side of the flexible layer; a second adhesive layer on said second side of the flexible layer; wherein said first adhesive layer is stuck to the top surface of a drain shoe; and wherein said second adhesive layer is stuck to the bottom surface of the bathtub to secure the drain shoe up against said bottom surface, so that a plumber can release the drain assembly and the drain assembly will remain affixed to the bottom surface of the bathtub.
 7. A combination as in claim 6, wherein said bathtub is a portion of a combined bathtub and shower unit.
 8. A method of installing waste and overflow assemblies on a combined bathtub and shower unit, comprising the following steps of: using a self-adhesive washer having a flexible layer having a first side and a second side; a first adhesive layer on said first side of the flexible layer; a second adhesive layer on said second side of the flexible layer; attaching said drain shoe with said second adhesive layer to a bottom surface of a bathtub by means of the second adhesive layer sticking to the bottom surface of the bathtub; and installing a strainer from a top surface of said bathtub.
 9. A method of installing waste and overflow assemblies as in claim 8, wherein said self-adhesive washer comprises a first release liner on said first adhesive layer, and wherein said first release liner is removably secured to said first adhesive layer and after removing said first release liner said first adhesive layer is secured to a top surface of said drain shoe.
 10. A method of installing waste and overflow assemblies as in claim 8, wherein said self-adhesive washer comprises a second release liner on said second adhesive layer, and wherein said second release liner is removably secured to said second adhesive layer and after removing said second release liner, said drain shoe and washer are attached to said bottom surface of the bathtub.
 11. A method of installing waste and overflow assemblies as in claim 8, wherein said self-adhesive washer is a circular shape.
 12. A method of installing waste and overflow assemblies as in claim 11, wherein said self-adhesive washer has a circular inner diameter and a circular outer diameter.
 13. A method of installing waste and overflow assemblies as in claim 8, wherein said bathtub is a portion of a combined bathtub and shower unit.
 14. A method of installing waste and overflow assemblies as in claim 8, wherein said flexible layer is compressible foam.
 15. A method of installing waste and overflow assemblies as in claim 8, wherein said flexible layer is cellular plastic.
 16. A method of installing waste and overflow assemblies as in claim 8, further comprising providing a centering tool releasably and threadably engaging said drain shoe and extending up from the drain shoe to align the drain shoe and washer around a drain hole.
 17. A method of installing waste and overflow assemblies as in claim 16, wherein said centering tool is inserted into said drain hole from the bottom of the bathtub, and, upon lifting the drain shoe up toward the drain hole with the centering tool inside the drain hole, said washer affixes the drain shoe to the bottom surface of the bathtub.
 18. A method of installing waste and overflow assemblies as in claim 16, wherein said centering tool is cylindrical.
 19. A method of installing waste and overflow assemblies as in claim 18, wherein said centering tool comprises a threaded lower portion for threadably engaging the drain shoe and a non-threaded upper portion for being inserted into the drain hole. 